Determination of cerebrospinal fluid gentamicin in the beagle using an indwelling cerebral ventricular cannula.

This study compared the concentrations of gentamicin in the blood and cerebrospinal fluid (CSF) of young beagles. Indwelling cannulas were surgically implanted into the external jugular vein and the left lateral cerebral ventricle of two 5-month-old beagles. Gentamicin was given intravenously (10 mg/kg) and CSF and blood samples were taken. This was repeated in 1 dog three times over 42 days. CSF collected 2 weeks after cannula implantation was cytologically normal. Significant levels of gentamicin were detected in the CSF shortly after injection in the absence of inflammation. Levels persisted when inflammation was present. The use of an indwelling ventricular cannula was effective for the long-term monitoring of CSF drug levels.